The following relates to the illumination arts, lighting arts, solid state lighting arts, and related arts.
A directional lamp is defined by the US Department of Energy in its Energy Star Eligibility Criteria for Integral LED Lamps, draft 3, as a lamp having at least 80% of its light output within a cone angle of 120 degrees (full-width at half-maximum of intensity, FWHM). Directional lamps include “flood” lamps having relatively broad beam patterns, and “spot” lamps having substantially narrower beam patterns (e.g., having a beam intensity distribution characterized by a FWHM<20°, with some lamp standards specified for angles as small as 6-10° FWHM).